Ray Hilborn and I don’t agree on much. But apparently, we do agree that “Marine parks are fishy”, in Ray’s words, or that they “suck” in mine. Or at least that is what I recently told an audience at the Benthic Ecology Meeting (more on this soon). No, no. I love the concept of Marine Protected Areas. Yet most of the MPAs I work in do little to conserve or restore fish (too small, too much poaching, etc) and do nothing to mitigate other threats, particularly threats to unharvested species like corals and algae. I don’t agree with everything in Ray’s piece (below), but I do very much agree this:
“There are many threats to marine ecosystems, including oil spills, exotic species, runoff from terrestrial sources, illegal fishing, excessive legal fishing, ocean acidification, and global warming. The marine parks movement does not recognize that most “protected areas” only “protect” from legal fishing, and not much else. Advocates argue that unfished ecosystems are more resilient to environmental perturbations such as exotic species, yet the same argument, if valid, must apply to areas outside of reserves. Since fishing pressure has been redirected to unprotected areas, those ecosystems ought to be more vulnerable to the same perturbation.”
I think Ray’s point about the potential intensification of fishing outside of MPAs leading to a reduction in ecosystem resilience to be particularly novel. It really undercuts the “resilience movement’s” fundamental argument. Although a reasonable response to this point is that well-designed MPAs displace fishing intensity, but by increasing stock size and production, they actually reduce overall fishing impact, i.e., via spillover effects. I’ll ask Ray and Boris Worm about this today at the panel discussion “Are fisheries turning the corner” at Duke hosted by the Nicholas Institute.
In “Conservation in the Anthropocene,” Peter Kareiva, Robert Lalasz, and Michelle Marvier argue that conservation needs to move beyond parks and protected areas. They stress that ecosystems are generally resilient to perturbation, and rather than being irreparably damaged by the slightest anthropogenic impact, ecosystems can both support biodiversity and produce sustainable goods and services. While their arguments and examples are drawn from terrestrial ecosystems, much of their article is relevant to marine ecosystems, my field of study.
Marine ecosystems are the new frontier for conservation. And much of the funding for new scientific work has been directed towards the establishment of protected areas. It’s important to note that while marine and terrestrial ecosystems share much in common, there are differences. One fundamental difference is the nature of human use. In terrestrial ecosystems, a dominant form of use is agriculture, which essentially rips out native ecosystems and replaces them with exotic species: crops, tree plantations, or grasses for grazing. Agriculture makes no pretense about preserving natural ecosystems.
In contrast, in marine ecosystems, we attempt to sustainably harvest the natural ecosystem. We leave the lower trophic levels — primary producers and most of their consumers — untouched, and exploit only the higher trophic levels. This has profound consequences. It means that even if the dreams of protecting 10 percent of the world’s ocean, as set out in the 1992 Convention on Biodiversity, were to come true, most marine biodiversity will remain outside the boundaries. The struggle to maintain biodiversity is in the total anthropocene ocean; it will never be achieved through protected areas.
The marine conservation movement has been slow to grasp this. Similarly, it has failed to see that closing areas to fishing does not eliminate fishing pressure, it simply moves it. When an area is closed, fishing efforts concentrate outside protected areas. Consequently, simple comparisons of abundance inside and outside of reserves as a measure of “success” are meaningless. The salient question to ask is what happens to the total abundance.
One study sought to answer this question by tracking trends in abundance inside and outside of a set of reserves established in the California Channel Islands.1 Of the species targeted by commercial and recreational fishing, abundance went up inside reserves and down on the outside. Since 80 percent of the habitat is outside of the reserves, the data suggest that the total abundance of the targeted fish species actually declined. The gains inside were more than offset by the decreases on the outside.
In the case of the Channel Islands reserves, the creation of a protected area had a negative impact on abundance. In many other cases, protected areas have little to no impact. Two of the most heralded successes of the marine conservation movement have been the establishment of large protected areas in the Northwestern Hawaiian Islands, and the western Pacific US territories. If the measure of success is the amount of area proclaimed as protected, these are significant achievements. But if the objective is effective protection against real threats, the achievement is less because there was little, if any, human impact in those areas before protection.
There are many threats to marine ecosystems, including oil spills, exotic species, runoff from terrestrial sources, illegal fishing, excessive legal fishing, ocean acidification, and global warming. The marine parks movement does not recognize that most “protected areas” only “protect” from legal fishing, and not much else. Advocates argue that unfished ecosystems are more resilient to environmental perturbations such as exotic species, yet the same argument, if valid, must apply to areas outside of reserves. Since fishing pressure has been redirected to unprotected areas, those ecosystems ought to be more vulnerable to the same perturbation.
Kareiva et al. argue that the new conservation “requires conservation to embrace marginalized and demonized groups,” and perhaps no group has been so demonized by the environmental movement as fishermen. Terms like “roving bandits” and “rapers and pillagers” permeate the public discussion. But luckily this is changing. The new marine conservation movement recognizes that conserving biodiversity requires more than merely controlling fishing. Progressive NGOs are working with fishing groups rather than demonizing them, a transformation that has entered into in marine conservation debates that attempt to find new solutions to the environmental impacts of fishing.
Kareiva et al. close by stating, “Protecting biodiversity for its own sake has not worked. Protecting nature that is dynamic and resilient, that is in our midst rather than far away, and that sustains human communities — these are the ways forward now.” This is as true in the marine world as in the terrestrial. There is certainly a role for protected areas. But the bulk of marine biodiversity will always be in the dynamic areas outside of them, areas that must be sustainably managed as we go forward.
Ray Hilborn is a professor in the school of Aquatic and Fishery Sciences at the University of Washington.
1. Hamilton, S. L., J. E. Caselle, D. P. Malone, and M. H. Carr. 2010. “Incorporating biogeography into evaluation of the Channel Islands marine reserve network.” Proceedings of the National Academy of Sciences of the United States of America. www.pnas.org/cgi/doi/10.1073/pnas.0908091107. (back)